The present invention relates to an airbag device for protecting an occupant in a vehicle. More particularly, the present invention relates to an airbag device that includes a twin type airbag with a left side and a right side to be inflated at a front left side and a front right side of an occupant, respectively.
Japanese Patent Publication (Kokai) No. 04-292239 (incorporated by reference herein in its entirety) has disclosed an airbag for protecting an occupant in case of a car crash and the like. The airbag includes a left half airbag and a right half airbag to be inflated by a common inflator on a front left side and a front right side of the occupant, respectively. In the airbag, front ends of the left half airbag and the right half airbag are joined together with a tie panel.
The airbag is housed in a casing in a folded state and covered with a cover. When the inflator (gas generator) is activated to eject gas in case of a car crash, the airbag pushes the cover to open, and is inflated in front of the occupant. The inflator is disposed inside or outside a base-end of the airbag. When an airbag system has the inflator outside the base-end of the airbag, the gas from the inflator is supplied into the airbag through a gas inlet at the base-end of the airbag. When the inflator is arranged inside the base-end of the airbag, the entire portion or a part of the inflator may be disposed in the airbag. The latter example includes a structure in which a pair of slit openings is provided in the airbag for inserting a rod-like inflator, and both ends of the inflator project to the exterior of the airbag.
In the airbag disclosed in Japanese Patent Publication (Kokai) No. 04-292239, the airbag is substantially formed of only the left half airbag and the right half airbag, and an interior thereof has two hollow chambers at left and right sides. When the left half airbag and the right half airbag are inflated, the gas from the inflator may flow into one of the half airbags more than that flowing into the other, and the one of the half airbags is inflated faster than the other of the half airbags. Also, the front ends of the left half airbag and the right half airbag are connected together with a tie panel. Accordingly, when the airbag is inflated, the tie panel receives a lateral center of the occupant body.
U.S. Patent Publication No. 2004/0195807 describes a twin airbag and is incorporated by reference herein in its entirety.
In view of the problems described above, the present invention has been made, and an object of the present invention is to provide an airbag and an airbag system having a base-end chamber connected to hollow chambers at left and right sides, in which the base chamber is inflated faster than the left and right half airbags.
Another object of the present invention is to provide an airbag and an airbag system in which both of the left half airbag and the right half airbag are inflated substantially equally.
A further object of the present invention is to provide an airbag and an airbag system in which the left half airbag receives a left thorax of the occupant and the right half airbag receives a right thorax of the occupant, and a space between the half airbags faces a lateral center of the thorax of the occupant, and to provide a vehicle provided with the airbag system.
Further objects and advantages of the invention will be apparent from the following description of the invention.